1. Field of the Invention
Exemplary embodiments of the present invention relate to a lighting apparatus and, more particularly, to a lighting apparatus without color temperature change, which is capable of adjusting a width and a color of light.
2. Discussion of the Background
In general, a light-emitting diode (LED) has qualities such as high efficiency, long lifespan, low power consumption, environmentally-friendly, etc., as a light source. Therefore, the LED is widely used in various industrial fields.
A conventional LED lighting apparatus emits white light by mixing red light generated by a red LED, green light generated by a green LED, and blue light generated by a blue LED. Alternatively a conventional LED lighting apparatus emits white light by a white LED employing a blue LED chip and yellow fluorescent substance converting a portion of blue light generated by the blue LED into yellow light to mix the yellow light with a remaining blue light in order to generate white light. In the conventional LED lighting apparatus, the LED lighting apparatus employing a blue LED chip and yellow fluorescent substance occupies a major area.
In general, an LED emits heat, so that the fluorescent substance in the LED may be damaged by the heat. Therefore, when the LED is used for a long period of time, the fluorescent substance in the LED may become discolored, resulting in the desired white light to be changed into another colored light. Furthermore, when a lighting apparatus employing this type of LED is equipped in a confined space, the change in white color or discoloration may have serious effects.